Bearing cavity sealing device and aero-engine

Abstract

The invention discloses a bearing cavity sealing device and an aero-engine. The bearing cavity sealing device comprises a mounting seat for mounting a bearing, a rotating shaft fixedly mounted in the bearing, and a dynamic sealing element and a static sealing element which are sequentially mounted in a bearing cavity in the radial direction of the rotating shaft; the movable sealing piece comprises a sealing runway arranged on the rotating shaft in an interference sleeving mode and a locking structure used for locking the sealing runway to the rotating shaft in the radial direction, and the locking structure is arranged between the sealing runway and the bearing and is in clamping fit with the sealing runway to form a check ring structure used for preventing leaked gas from impacting the bearing; the static sealing piece comprises a sealing shell installed on the installation base in a sealed mode and a graphite sealing piece installed on the sealing shell in a sealed mode. The graphite sealing piece is arranged at the end, away from the bearing, of the locking structure and is in clearance fit with the sealing runway to form a main sealing interface used for sealing the bearing cavity. The structure is compact, the radial size is small, the linear speed is effectively reduced, and the requirements for long service life and high performance of the aero-engine are met.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengine sealing, and in particular to a bearing cavity sealing device and an aeroengine comprising the bearing cavity sealing device. Background Art

[0002] The main function of the aircraft engine bearing cavity seal is to effectively isolate the bearing cavity of the engine rotor system from the engine's airflow environment, protect the bearing and lubricating oil from damage by the airflow path environment, and prevent lubricating oil leakage. The sealing method of the bearing cavity of the traditional aircraft gas turbine propeller engine usually adopts a comb seal, which is a non-contact sealing structure. There is a gap between the rotor and the stator, and the leakage is large. In addition, during the acceleration process of the aircraft engine from the slow state to the maximum power state, the centrifugal force will inevitably cause the rotor and the stator to collide and rub, resulting in the wear of the comb tooth tip and the coating, causing an irreversible permanent increase in the gap, and the sealing effect will continue to decline during use.

[0003] As the thrust ratio, high pressure ratio and high temperature ratio of aircraft engines continue to increase, the linear speed, sealing pressure difference and operating temperature of the main shaft seal continue to increase, and the operating conditions are becoming increasingly severe. The traditional non-contact grate seal is used in aircraft engines with high sealing pressure difference, which will cause high bearing cavity temperature and large lubricating oil consumption, causing great loss to engine performance. Therefore, the bearing cavity seal gradually adopts a new type of non-contact floating ring seal to replace the grate seal. The non-contact floating ring seal is generally composed of a shell, a graphite ring, a wave spring, a gasket and a retaining ring. The graphite ring and the rotating sealing runway form the main sealing interface to limit the leakage of axial lubricating oil. The corrugated spring makes the end face of the graphite ring close to the inner side of the shell to form an auxiliary sealing interface. During operation, the sealing runway of the floating ring seal stator can form radial buoyancy, so that the graphite ring floats radially to adapt to the rotor eccentricity and follow the runway jump. However, in advanced aircraft engines, the high-pressure turbine is usually supported on the low-pressure turbine, and the spatial position of the bearing cavity seal is limited, so a compact inter-axial sealing device is required. The existing floating ring seal structure occupies a large space, resulting in a large radial dimension of the floating ring seal structure, resulting in a large linear speed of the main shaft seal. The large linear speed will intensify the relative movement between the floating ring seal structure and the rotor, resulting in faster wear of the floating ring seal structure, increased leakage, and affected sealing effect, resulting in a high application risk of the engine. In addition, the non-contact floating ring seal allows a small amount of high-pressure side gas to leak into the bearing cavity to prevent the lubricating oil in the bearing cavity from leaking out, but the gap of the existing floating ring seal structure is aligned with the bearing, resulting in the high-pressure side gas leaking from the gap being directly sprayed onto the outer ring of the bearing, the end face of the cage or the rolling element, causing the bearing temperature to rise, affecting the safety of the engine. Summary of the invention

[0004] The present invention provides a bearing cavity sealing device and an aero-engine, so as to solve the technical problem in the prior art that the radial dimension of the bearing cavity sealing device is large, resulting in high linear speed and affecting the engine performance.

[0005] According to one aspect of the present invention, there is provided a bearing cavity sealing device, comprising a mounting seat for mounting a bearing, a rotating shaft fixedly mounted in the bearing, and a dynamic seal and a static seal sequentially mounted in the bearing cavity along the radial direction of the rotating shaft;

[0006] The dynamic seal comprises a sealing track which is sleeved on the rotating shaft and a locking structure for radially locking the sealing track on the rotating shaft. The locking structure is arranged between the sealing track and the bearing and is engaged with the sealing track to form a retaining ring structure for preventing the leakage gas from impacting the bearing.

[0007] The static seal includes a sealing shell sealingly mounted on a mounting seat and a graphite seal sealingly mounted on the sealing shell. The graphite seal is arranged at one end of the locking structure away from the bearing and cooperates with the sealing track gap to form a main sealing interface for sealing the bearing cavity.

[0008] Furthermore, the inner wall of the mounting seat is axially arranged in sequence with a limiting ring platform for sealingly mounting the sealing housing and a limiting groove for installing the bearing retaining ring. The bearing retaining ring and the sealing housing are respectively arranged on both sides of the bearing and abut against the end face of the bearing outer ring for axial limitation.

[0009] Furthermore, one end of the sealing shell close to the bearing is bent toward the mounting seat to form a limiting step. The sealing shell is interference mounted on the inner wall of the limiting ring and is axially abutted and sealed with the limiting ring through the limiting step. A limiting boss for axially limiting the graphite seal is radially arranged on the inner wall of the sealing shell away from the limiting step.

[0010] Furthermore, the graphite seal comprises a limit ring, an elastic member and a graphite ring assembly which are sequentially arranged along the axial direction of the rotating shaft toward the bearing, and the limit ring is inserted and fixed in the sealing housing along the radial direction and axially fixed to the elastic member;

[0011] The limiting retaining ring is parallel to the limiting boss, and two sides of the graphite ring assembly are axially abutted against the elastic member and the limiting boss respectively to form an auxiliary sealing interface.

[0012] Furthermore, an anti-rotation ring is radially arranged on the inner wall of the sealing track, and the anti-rotation ring is arranged at one end of the sealing track away from the bearing, and is used to be clamped on the end of the rotating shaft for axial limitation;

[0013] A plurality of anti-rotation grooves are radially spaced apart on the anti-rotation ring, and a plurality of protrusions are correspondingly arranged on the rotating shaft along the axial direction. The anti-rotation ring is radially limited by plugging the anti-rotation grooves and the protrusions to prevent relative rotation between the sealing track and the rotating shaft.

[0014] Furthermore, a plurality of anti-rotation bosses are radially arranged on the outer wall of the sealing track, and the anti-rotation bosses are arranged at one end of the sealing track close to the bearing and are locked with the locking structure;

[0015] The anti-rotation boss is arranged between the main sealing interface and the bearing and is arranged axially corresponding to the anti-rotation groove.

[0016] Furthermore, a drawing groove is provided at one end of the inner wall of the sealing runway away from the bearing, and the drawing groove is arranged on a side of the anti-rotation ring away from the bearing.

[0017] Furthermore, the locking structure includes a locking nut abutting against the inner ring of the bearing and a mounting ring fixed to the locking nut at one end away from the bearing. The inner wall of the mounting ring is radially spaced apart with a plurality of snap-in grooves corresponding to the anti-rotation boss. The anti-rotation boss is radially inserted into the snap-in grooves and axially fits and seals with the end face of the locking nut.

[0018] Furthermore, a snap ring groove is radially opened on the inner wall of the mounting ring, which is arranged on the side of the snap groove away from the locking nut and is used to install an air blocking ring to further prevent the impact of gas leaking into the bearing cavity on the bearing.

[0019] According to another aspect of the present invention, an aircraft engine using the bearing cavity sealing device is also provided.

[0020] The present invention has the following beneficial effects:

[0021] 1. The mounting seat in the present invention can perform integrated installation of the bearing and the static seal, which can simplify the structure and the number of parts, reduce the occupied space, make the overall structure compact, and meet the installation requirements of the aircraft engine. The static seal is installed in the mounting seat through the provided sealing housing, which can reduce the radial size of the static seal to reduce the linear speed and reduce the impact on the engine performance;

[0022] 2. The present invention provides a locking structure on the rotating shaft to radially lock the sealing track on the rotating shaft, and reduces the radial size of the bearing cavity sealing device by reducing the radial gap between the sealing track and the rotating shaft, thereby greatly reducing the linear speed of the bearing cavity sealing device, reducing the relative movement between the bearing cavity sealing device and the rotating shaft to reduce wear and leakage, improve the sealing effect, improve the thrust and efficiency of the engine, reduce fuel consumption, and avoid subjecting the bearing cavity sealing device to greater thermal stress and mechanical stress, reduce the risk of fatigue damage, and increase the service life of the engine;

[0023] 3. The locking structure and the sealing track seal lock form a retaining ring structure, which can not only prevent the relative rotation between the sealing track and the rotating shaft, but also the retaining ring structure is arranged between the bearing and the main sealing interface, which can block the high-temperature, high-pressure sealing gas leaking from the gap of the main sealing interface, and prevent it from directly impacting the bearing outer ring, the cage end face or the rolling element, avoiding the bearing temperature from rising and ensuring the safety of the engine.

[0024] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 It is a structural schematic diagram of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0027] Figure 2 2 is a schematic structural diagram of a static seal of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0028] Figure 3 1 is a cross-sectional view of a sealing track of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0029] Figure 4 2 is a cross-sectional view II of the sealing track of the bearing cavity sealing device according to the preferred embodiment of the present invention;

[0030] Figure 5 1 is a cross-sectional view of a locking structure of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0031] Figure 6 It is a cross-sectional view II of the locking structure of the bearing cavity sealing device of the preferred embodiment of the present invention.

[0032] Legend:

[0033] 100, bearing; 200, rotating shaft; 300, mounting seat; 301, limiting ring platform; 302, bearing retaining ring; 400, dynamic seal; 401, sealing track; 4011, anti-rotation ring; 4012, anti-rotation groove; 4013, anti-rotation boss; 4014, drawing groove; 402, locking structure; 4021, locking nut; 4022, mounting ring; 4023, snap-on groove; 4024, snap-on ring groove; 500, static seal; 501, sealing housing; 5011, limiting boss; 5012, limiting step; 502, graphite seal; 5021, limiting retaining ring; 5022, elastic member; 5023, graphite ring assembly. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0035] like Figure 1 and Figure 2 As shown, the bearing cavity sealing device of this embodiment includes a mounting seat 300 for mounting a bearing 100, a rotating shaft 200 fixedly mounted in the bearing 100, and a dynamic seal 400 and a static seal 500 sequentially mounted in the bearing cavity along the radial direction of the rotating shaft 200. The dynamic seal 400 includes a sealing track 401 which is sleeved on the rotating shaft 200 and a locking structure 402 which is threadedly connected to the rotating shaft 200. The locking structure 402 is arranged between the sealing track 401 and the bearing 100 and is engaged with the sealing track 401 to form a retaining ring structure, which is used to radially lock the sealing track 401 on the rotating shaft 200 and prevent the leakage gas from impacting the bearing 100. The static seal 500 includes a sealing housing 501 sealingly mounted on the mounting seat 300 and a graphite seal 502 sealingly mounted on the sealing housing 501. The graphite seal 502 is arranged at one end of the locking structure 402 away from the bearing 100 and cooperates with the sealing track 401 to form a main sealing interface for sealing the bearing cavity.

[0036] When assembling the bearing cavity sealing device, the dynamic seal 400 is assembled first. Specifically, the rotating shaft 200 is fixedly mounted on the inner ring of the bearing 100 and then the mounting seat 300 is sleeved on the outside of the bearing 100, so that a bearing cavity is formed between the mounting seat 300 and the rotating shaft 200, and the locking structure 402 is threadedly connected to the rotating shaft 200 in the bearing cavity and abuts against the end face of the inner ring of the bearing 100 for sealing, and the sealing runway 401 is interference-sleeved on the side of the locking structure 402 away from the bearing 100 and is clamped and locked with the locking structure 402, and the end of the sealing runway 401 away from the locking structure 402 is clamped on the end face of the rotating shaft 200 for axial and radial limiting, thereby completing the installation of the dynamic seal 400. Thus, by providing a locking structure 402 on the rotating shaft 200 to radially lock the sealing runway 401 on the rotating shaft 200, relative rotation between the sealing runway 401 and the rotating shaft 200 can be prevented, and the radial gap between the sealing runway 401 and the rotating shaft 200 can be reduced to reduce the radial size of the bearing cavity sealing device, greatly reduce the linear speed of the bearing cavity sealing device, and reduce the relative movement between the bearing cavity sealing device and the rotating shaft 200 to reduce wear and leakage, improve the sealing effect, improve the thrust and efficiency of the engine, reduce fuel consumption, and at the same time avoid subjecting the bearing cavity sealing device to greater thermal stress and mechanical stress, reduce the risk of fatigue damage, and increase the service life of the engine.

[0037] The static seal 500 is then assembled. Specifically, the assembled graphite seal 502 is first sealed and installed in the sealing housing 501. The sealing housing 501 is then interference fit onto the mounting seat 300 in the bearing cavity from the side of the inner ring of the bearing 100 away from the sealing track 401, and is axially limited by the mounting seat 300. The outer ring of the bearing 100 is then installed on the outside of the inner ring of the bearing 100 from the side of the inner ring of the bearing 100 away from the sealing track 401, and is radially abutted and sealed with the mounting seat 300, so that a main sealing interface with a clearance fit is formed between it and the outer wall of the sealing track 401. Therefore, the bearing 100 and the static seal 500 can be integratedly installed through the set mounting seat 300, which can effectively simplify the structure and the number of parts, reduce the occupied space, and make the overall structure compact and highly reliable. The static seal 500 is installed in the mounting seat 300 through the set sealing shell 501, which can reduce the radial size of the static seal 500 to reduce the linear speed, thereby meeting the long-life high-performance bearing cavity sealing requirements.

[0038] When the present invention is working, the dynamic seal 400 is interference-fitted on the rotating shaft 200 and rotates synchronously with the rotating shaft 200, and the static seal 500 is interference-fitted on the mounting seat 300 and cooperates with the dynamic seal 400 to form a main sealing interface to seal the bearing cavity. A sealing gap is formed between the graphite seal 502 and the sealing track 401, and the graphite seal 502 can float radially to adapt to the eccentricity of the rotating shaft 200 and follow the jumping of the sealing track 401. The bearing cavity on the side of the main sealing interface close to the bearing 100 is the low-pressure side, and the side away from the bearing 100 is the high-pressure side, so that the sealing gas on the high-pressure side can enter the low-pressure side through the sealing gap to seal the bearing cavity, thereby preventing the lubricating oil in the bearing cavity from leaking out of the bearing cavity. A locking structure 402 is provided in the bearing cavity between the main sealing interface and the bearing 100, so as to be locked with the sealing track 401 to form a retaining ring structure, which can prevent the high-temperature, high-pressure sealing gas leaking from the sealing gap from directly aligning with the bearing 100 to impact the outer ring of the bearing 100, the end face of the retaining frame or the rolling element, thereby avoiding direct injection causing the temperature of the bearing 100 to rise, thereby ensuring the safety of the engine, and enabling the sealing track 401 to integrate the functions of sealing, blocking high-temperature gas, and preventing circumferential rotation, etc., with a high degree of functional integration, thereby greatly improving practicality.

[0039] like Figure 1 and Figure 2 As shown, the inner wall of the mounting seat 300 is provided with a limit ring 301 protruding toward the direction of the rotating shaft 200. The limit ring 301 is arranged on the side of the bearing 100 close to the static seal 500 for installing the sealing housing 501, so that the sealing housing 501 is sealed with the mounting seat 300 and is clamped with the limit ring 301 for axial limitation. The inner wall of the mounting seat 300 is provided with a limit groove in the radial direction. The limit groove is arranged on the side of the bearing 100 away from the static seal 500 for fixed installation of the bearing retaining ring 302. Therefore, the bearing retaining ring 302 and the sealing housing 501 are respectively arranged on both sides of the bearing 100 and axially abut against the end face of the outer ring of the bearing 100 to achieve axial limitation of the bearing 100.

[0040] like Figure 1 and Figure 2As shown, one end of the sealing housing 501 close to the bearing 100 is bent toward the mounting seat 300 to form a limiting step 5012, and a limiting boss 5011 is radially arranged on the inner wall of the sealing housing 501 at one end away from the limiting step 5012, and the graphite seal 502 is arranged on the side of the limiting boss 5011 away from the bearing cavity so as to perform axial limiting installation on the graphite seal 502 through the limiting boss 5011. When installing the sealing housing 501, the sealing housing 501 is axially penetrated from one end of the limiting groove on the mounting seat 300 toward one end of the limiting ring 301, so that the outer wall of the sealing housing 501 and the inner wall of the limiting ring 301 are interference-fitted to ensure the sealing effect between the sealing housing 501 and the mounting seat 300, and at the same time, the limiting step 5012 of the sealing housing 501 is axially engaged with the limiting ring 301 of the mounting seat 300 to limit the axial position. In addition, the outer wall of the limiting step 5012 is tightly fitted with the mounting seat 300, and the end of the limiting step 5012 is abutted against the outer ring of the bearing 100 to further ensure the sealing effect between the sealing housing 501 and the mounting seat 300. By integrating the sealing housing 501 with the mounting seat 300 and making it cooperate with the bearing retaining ring 302 to axially limit the bearing 100, the number of parts can be greatly reduced, the structure can be simplified, the occupied space can be reduced, and the installation requirements of the aircraft engine can be met.

[0041] like Figure 1 and Figure 2 As shown, the graphite seal 502 is arranged on the side of the limiting boss 5011 away from the bearing cavity, and includes a limiting retaining ring 5021, an elastic member 5022 and a graphite ring assembly 5023 which are arranged in sequence along the axial direction of the rotating shaft 200 toward the bearing 100. The limiting retaining ring 5021 is radially inserted and fixed in the sealing housing 501 and axially fixed with the elastic member 5022. The limiting retaining ring 5021 is arranged parallel to the limiting boss 5011, so that a space for installing the elastic member 5022 and the graphite ring is formed between the limiting boss 5011 and the limiting retaining ring 5021, and the two sides of the graphite ring assembly 5023 are axially abutted against the elastic member 5022 and the limiting boss 5011 to form an auxiliary sealing interface.

[0042] Specifically, the elastic member 5022 includes a spring arranged axially and a gasket arranged at both ends of the spring and fixedly connected to the spring. The gasket on the side away from the graphite ring assembly 5023 is fixed on the limiting ring 5021. Under the elastic action of the spring, the gasket close to the graphite ring assembly 5023 generates an extrusion force toward the graphite ring assembly 5023, so that the graphite ring assembly 5023 is pressed axially onto the limiting boss 5011, so that the two ends of the graphite ring assembly 5023 are axially abutted against the gasket and the limiting boss 5011 respectively to form an auxiliary sealing interface, which can effectively reduce the impact of axial movement of the rotating shaft 200 and further enhance the sealing effect. At the same time, the inner wall of the graphite ring assembly 5023 and the outer wall gap of the sealing runway 401 cooperate to form a main sealing interface, so there is a sealing gap between it and the sealing runway 401, so that it can float radially to adapt to the eccentricity of the rotating shaft 200 and follow the jumping of the sealing runway 401 to form a non-contact floating ring seal. This method can effectively reduce wear and improve engine performance.

[0043] like Figure 1 , Figure 3 and Figure 4 As shown, the inner wall of the sealing track 401 close to the bearing 100 is set as an interference surface that is interference fit with the rotating shaft 200. The sealing track 401 is interference-sleeved on the rotating shaft 200 so that it rotates synchronously with the rotating shaft 200 to form a dynamic seal, thereby preventing the leakage of lubricating oil between the sealing track 401 and the rotating shaft 200 and ensuring the sealing effect. An anti-rotation ring 4011 is radially arranged on the inner wall of the sealing track 401 away from the bearing 100. The anti-rotation ring 4011 is axially clamped on the end of the rotating shaft 200 for limiting and tightly fitting with the end face of the rotating shaft 200, and a plurality of anti-rotation grooves 4012 are radially spaced apart on the anti-rotation ring 4011, and a plurality of protrusions are correspondingly arranged axially on the rotating shaft 200. The anti-rotation ring 4011 circumferentially limits the sealing track 401 through the plug-in cooperation between the anti-rotation grooves 4012 and the protrusions. On the one hand, relative rotation between the sealing track 401 and the rotating shaft 200 can be prevented, so that the installation of the sealing track 401 on the rotating shaft 200 is stable and reliable, ensuring that the sealing track 401 is not affected by the radial runout and axial movement of the rotating shaft 200, and rotates synchronously with the rotating shaft 200. On the other hand, the leakage of lubricating oil between the sealing track 401 and the rotating shaft 200 can be further prevented.

[0044] The number, shape and size of the anti-rotation grooves 4012 of the sealing track 401 match the protrusions at the end of the rotating shaft 200 to prevent the generation of an unbalanced amount of the rotating shaft 200. Preferably, the protrusions at the end of the rotating shaft 200 are evenly spaced along the circumference, and the number thereof is generally 6-12. The number of the anti-rotation grooves 4012 is the same as the number of the protrusions for easy installation; preferably, the size of the anti-rotation grooves 4012 is slightly larger than the size of the protrusions so that the protrusions can be smoothly inserted into the anti-rotation grooves 4012. Thus, by snap-fitting the protrusions and the anti-rotation grooves 4012, the circumferential limit of the sealing track 401 can be achieved to prevent the sealing track 401 and the rotating shaft 200 from rotating relative to each other.

[0045] like Figure 3 and Figure 4 As shown, a drawing groove 4014 is also provided at one end of the inner wall of the sealing runway 401 away from the bearing 100, and the drawing groove 4014 is arranged on the side of the anti-rotation ring 4011 away from the bearing 100. The setting of the drawing groove 4014 can provide a fulcrum for the operator, and the sealing runway 401 can be installed on the rotating shaft 200 or removed from the rotating shaft 200 by holding the drawing groove 4014, which saves time and effort and improves the assembly and disassembly efficiency. A chamfer is also provided at one end of the outer wall of the sealing runway 401 away from the bearing 100 to guide the installation of the graphite ring, to prevent the graphite ring assembly 5023 from being scratched or damaged by the sharp edge of the sealing runway 401 during the process of assembling it to the outer wall of the sealing runway 401, and to avoid affecting the sealing effect of the graphite ring assembly 5023.

[0046] like Figure 1 , Figure 3 and Figure 4 As shown, the outer wall of the sealing track 401 is a mating surface for gap matching with the graphite ring assembly 5023. The outer wall of the sealing track 401, which is close to the bearing 100, extends radially toward the bearing cavity to form an anti-rotation boss 4013. A plurality of anti-rotation bosses 4013 are arranged at radial intervals along the sealing track 401. The anti-rotation bosses 4013 are arranged in the bearing cavity between the main sealing interface and the bearing 100, and are tightly fitted and locked with the locking structure 402, so that the anti-rotation bosses 4013 are arranged in a On the one hand, it can block the high-temperature, high-pressure sealing gas that leaks from the main sealing interface to the bearing cavity, prevent it from directly impacting the bearing 100, avoid impacting the outer ring of the bearing 100, the end face of the retaining frame or the rolling element causing the temperature of the bearing 100 to rise, and improve the safety performance of the engine. On the other hand, the circumferential limitation of the sealing runway 401 can be achieved through the snap-fit ​​cooperation between the anti-rotation boss 4013 and the locking structure 402, preventing relative rotation between it and the rotating shaft 200, thereby ensuring that the sealing runway 401 is installed stably and reliably.

[0047] like Figure 1 , Figure 5 and Figure 6 As shown, the locking structure 402 is arranged in the bearing cavity, including a locking nut 4021 abutting against the inner ring of the bearing 100 and a mounting ring 4022 fixed to the end of the locking nut 4021 away from the bearing 100. Specifically, the locking nut 4021 is arranged between the sealing track 401 and the bearing 100 and is threadedly connected to the sealing track 401, and the two ends of the locking nut 4021 are respectively abutted and sealed against the anti-rotation boss 4013 and the inner ring of the bearing 100, and the mounting ring 4022 is arranged on the outer periphery of the locking nut 4021 and has a radial distance with the sealing housing 501 to ensure the relative rotation between the dynamic seal 400 and the static seal 500, avoid radial collision between the two during relative rotation, and ensure safety. The inner wall of the mounting ring 4022 is provided with a plurality of snap-in grooves 4023 at intervals along the radial direction. The snap-in grooves 4023 and the anti-rotation boss 4013 are arranged correspondingly to each other for the anti-rotation boss 4013 of the sealing track 401 to be inserted and snap-fitted to form a retaining ring structure. The anti-rotation boss 4013 and the end face of the locking nut 4021 are tightly sealed. Therefore, the retaining ring structure can not only circumferentially limit the sealing track 401, further prevent relative rotation between it and the rotating shaft 200, and ensure the sealing effect between the sealing track 401 and the rotating shaft 200, but also the retaining ring structure is arranged in the bearing cavity between the main sealing interface and the bearing 100, so as to protect the bearing 100 and prevent the high-temperature and high-pressure sealing gas leaking from the sealing gap of the main sealing interface from entering the bearing cavity and directly impacting the outer ring of the bearing 100, the end face of the retaining frame or the rolling element, thereby avoiding direct injection causing the temperature of the bearing 100 to rise, thereby improving the safety and service life of the engine. The inner wall of the mounting ring 4022 is also radially provided with a snap ring groove 4024 , which is arranged on the side of the snap groove 4023 away from the locking nut 4021 and is used to install an air blocking ring to further prevent the gas leaking into the bearing cavity from impacting the bearing 100 .

[0048] The number, shape and size of the anti-rotation bosses 4013 should match the snap-in grooves 4023 in the mounting ring 4022 to prevent the generation of an unbalanced amount of the rotating shaft 200. Preferably, the snap-in grooves 4023 are evenly spaced along the circumference of the mounting ring 4022, and the number thereof is generally 6, 8, 10 or 12. The positions of the anti-rotation bosses 4013 on the sealing runway 401 correspond to the snap-in grooves 4023 for easy snap-in installation, and the number of the anti-rotation bosses 4013 can be adaptively adjusted according to the number of snap-in grooves 4023, but should be less than or equal to the number of snap-in grooves 4023; preferably, the size of the anti-rotation bosses 4013 is slightly smaller than the size of the snap-in grooves 4023 so that the anti-rotation bosses 4013 can be smoothly inserted. In the clamping groove 4023, by inserting the anti-rotation boss 4013 into the clamping groove 4023, not only can the circumferential limitation of the sealing runway 401 be achieved to prevent relative rotation between the sealing runway 401 and the rotating shaft 200, but also the sealing runway 401 can be radially locked on the rotating shaft 200 to reduce the radial distance between the sealing runway 401 and the rotating shaft 200, thereby reducing the overall radial size of the bearing cavity sealing device, greatly reducing its linear speed, ensuring the sealing effect while meeting the long life and high performance requirements of the aircraft engine.

[0049] Preferably, in this embodiment, if Figure 4 As shown, the anti-rotation boss 4013 of the sealing track 401 is axially corresponding to the anti-rotation groove 4012. It is only necessary to adjust the position of the snap-in groove 4023 of the locking structure 402 to correspond to the anti-rotation boss 4013 of the sealing track 401, so that the position of the anti-rotation groove 4012 of the sealing track 401 can be synchronously corresponding to the position of the protrusion on the end face of the rotating shaft 200, thereby saving adjustment time and greatly improving assembly efficiency.

[0050] According to another aspect of the present invention, the present invention further provides an aircraft engine having a bearing cavity sealing device as described in any one of the above items.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bearing cavity sealing device, characterized in that: It comprises a mounting seat (300) for mounting a bearing (100), a rotating shaft (200) fixedly mounted in the bearing (100), and a dynamic seal (400) and a static seal (500) sequentially mounted in the bearing cavity along the radial direction of the rotating shaft (200); The dynamic seal (400) comprises a sealing track (401) which is interference-fitted on the rotating shaft (200) and a locking structure (402) for radially locking the sealing track (401) on the rotating shaft (200); the locking structure (402) is arranged between the sealing track (401) and the bearing (100) and is engaged with the sealing track (401) to form a retaining ring structure, which is used to prevent leaking gas from impacting the bearing (100); The static seal (500) comprises a sealing housing (501) sealingly mounted on the mounting seat (300) and a graphite seal (502) sealingly mounted on the sealing housing (501); the graphite seal (502) is arranged at one end of the locking structure (402) away from the bearing (100) and is gap-matched with the sealing track (401) to form a main sealing interface for sealing the bearing cavity.

2. The bearing cavity sealing device according to claim 1, characterized in that: The inner wall of the mounting seat (300) is provided with a limiting ring platform (301) for sealingly mounting the sealing housing (501) and a limiting groove for mounting a bearing retaining ring (302) in sequence along the axial direction; the bearing retaining ring (302) and the sealing housing (501) are respectively arranged on both sides of the bearing (100) and abut against the end surface of the outer ring of the bearing (100) for axial limiting.

3. The bearing cavity sealing device according to claim 2, characterized in that: One end of the sealing housing (501) close to the bearing (100) is bent toward the mounting seat (300) to form a limiting step (5012); the sealing housing (501) is interference-mounted on the inner wall of the limiting ring (301) and is axially abutted and sealed with the limiting ring (301) through the limiting step (5012); and a limiting boss (5011) for axially limiting the graphite seal (502) is radially arranged on the inner wall of the sealing housing (501) away from the limiting step (5012).

4. The bearing cavity sealing device according to claim 3, characterized in that: The graphite seal (502) comprises a limit ring (5021), an elastic member (5022) and a graphite ring assembly (5023) which are sequentially arranged along the axial direction of the rotating shaft (200) and in the direction toward the bearing (100); the limit ring (5021) is radially inserted and fixed in the sealing housing (501) and is axially fixed to the elastic member (5022); The limiting retaining ring (5021) is parallel to the limiting boss (5011), and two sides of the graphite ring assembly (5023) are axially abutted against the elastic member (5022) and the limiting boss (5011) respectively to form an auxiliary sealing interface.

5. The bearing cavity sealing device according to claim 1, characterized in that: An anti-rotation ring (4011) is radially arranged on the inner wall of the sealing track (401); the anti-rotation ring (4011) is arranged at one end of the sealing track (401) away from the bearing and is used to be clamped on the end of the rotating shaft (200) for axial limitation; The anti-rotation ring (4011) is provided with a plurality of anti-rotation grooves (4012) spaced apart in the radial direction, and the rotating shaft (200) is provided with a plurality of protrusions correspondingly in the axial direction. The anti-rotation ring (4011) is radially limited by plugging and fitting the anti-rotation grooves (4012) with the protrusions, so as to prevent relative rotation between the sealing track (401) and the rotating shaft (200).

6. The bearing cavity sealing device according to claim 5, characterized in that: The outer wall of the sealing track (401) is provided with a plurality of anti-rotation bosses (4013) along the radial direction, and the anti-rotation bosses (4013) are arranged at one end of the sealing track (401) close to the bearing (100) and are locked with the locking structure (402); The anti-rotation boss (4013) is arranged between the main sealing interface and the bearing (100) and is axially arranged corresponding to the anti-rotation groove (4012).

7. The bearing cavity sealing device according to claim 5, characterized in that: A drawing groove (4014) is also provided at one end of the inner wall of the sealing track (401) away from the bearing (100), and the drawing groove (4014) is arranged on a side of the anti-rotation ring (4011) away from the bearing (100).

8. The bearing cavity sealing device according to claim 6, characterized in that: The locking structure (402) comprises a locking nut (4021) abutting against the inner ring of the bearing (100) and a mounting ring (4022) fixed to the end of the locking nut (4021) away from the bearing (100), the inner wall of the mounting ring (4022) being provided with a plurality of snap-in grooves (4023) corresponding to the anti-rotation boss (4013) at radial intervals, the anti-rotation boss (4013) being radially inserted into the snap-in grooves (4023) and axially fitting and sealing with the end face of the locking nut (4021).

9. The bearing cavity sealing device according to claim 8, characterized in that: The inner wall of the mounting ring (4022) is also provided with a snap ring groove (4024) in the radial direction. The snap ring groove (4024) is arranged on the side of the snap groove (4023) away from the locking nut (4021) and is used for installing an air blocking ring to further prevent the impact of gas leaking into the bearing cavity on the bearing.

10. An aircraft engine, characterized in that: A bearing cavity sealing device comprising the bearing cavity sealing device described in any one of claims 1 to 9.

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